网络编程2-UDP编程(DatagramSocket)

package com.udp.test;

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.SocketException;

import org.junit.Test;

public class TestUDP {
    private static String SERVER_HOST = "127.0.0.1";
    
    //发送端（和socket的客户端注意区别）
    @Test
    public void send(){
        //1、创建DatagramSocket对象
        DatagramSocket ds = null;
        try {
            ds = new DatagramSocket();
            //2、获取要传输的信息，创建数据包对象
            byte [] b = "Hello I am UDP test".getBytes();
            DatagramPacket dp = new DatagramPacket(b, 0, b.length,InetAddress.getByName(SERVER_HOST),8090);
            //3、发送数据包
            ds.send(dp);
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally{
            //4、关闭socket连接
            if(ds != null){
                ds.close();
            }
        }
    }
    
    //接受端（和socket的服务端区别）
    @Test
    public void receive(){
        //1、创建DatagramSocket对像
        DatagramSocket ds = null;
        try {
            ds = new DatagramSocket(8090);
            //2、创建数据包对象
            byte [] b = new byte[64];
            DatagramPacket dp = new DatagramPacket(b,0,b.length);
            //3、接收
            ds.receive(dp);
            //4、存到字符串dp.getData()方法
            String str = new String(dp.getData(),0,dp.getData().length);
            System.out.println(str);
        } catch (SocketException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally{
            
            //5、关闭ds
            if(ds != null ){
                ds.close();
            }
            
            
        }
        
    }
}